Device for drawing off fluid from fine granular material in centrifugal machines



Feb. 17, 1931,

1 ALTPETER DEVICE FOR DRAWING OFF' FLUID PROM FINE GRANULAR Filed Aug. l5 1928 VII MATERIAL IN CENTRIFUGAL MACHINES l NVENTOK:

\ UNITED .STA

Patented Felt. 1?', 1931 LUDWIG ALTPETER, OFTRIER, GERMANY `n'nvicn Foia- DRAWING orErLUIn rrtoiu` FINE GRANULAR MATERIAL in y CENTRIFUGAL MACHINES.

'Application ined August 15, 192s, serial No. 299,670, and in Germany August 19, 1927.

In centrifugal machines having an impervious drum jacket and in centrifugal machines of the type having two cups or cones it is well-known that the centrifugal force resulting from the high circumferential velocity causes separation of the material cen-4 trifuged into lighter and heavierv constituents so that the specically lighter constitubecause the granular material even after centrifuging still contains so-called voids which naturally fill with liquid.

Volumetrically the quantity of liquid may amount to of the solid material contained in the centrifuge after the withdrawal i of the water.

This quantity of liquid still remaining inA the centrifuged material after the normalj withdrawal of the water, which in most cases is highly disadvantageous for the subsequent Y employment of the solid material, for example in thercase of fine carbon, can be removed from the centrifuge during the continuous centrifuging operation neither by devices actuated from outside'norV by the methods known hitherto.

In order to overcome effectively the deiiciencies described above, according to the present invention in a centrifugal machine of the multiple cup or cone typev or in a machine with a cylindrical drum jacket one or more water withdrawal tubes or pockets are arranged in the drum jacket of the centrifuge so as to extend into the solid Zone of the material'centrifuged and are provided with orifices or bores for the liquid to be` drawn oil". Said tubes are constructed in a novel manner which enables during the uninterrupted centrifuging operation continual emergence of liquid from the material centrifugal without the solid constitutentsof said material being carried along therewith provided that they are specifically heavier Athan the liquid.

ythereof on'a larger scale and One embodiment of the invention is illus-V trated in Fig. l as applied to a twocup or cone centrifuge.

y 'Fig'. 2 being `a sectional view of a part action towards thevouter zone of the centrifuge so 'that clogging of the water withdrawal tubes ra and-"Carrying away of fine granular material is prevented by the grooves b and the obliquely disposed liquid out-flow passages c. This maybe seen more particularly from Figs. 3-5 in which the disposition of the granular material in` relationto the orifices c is evident`.` The grooves or recesses in front of the bores or orifices may be replaced by mere depressions and said grooves, recesses or depressions are not absolutely essential. Where they are not employed it is particularly advantageous to make the bores 0 conical outwardly or inwardly.V v

Since the bores c'overlap,-the possibility of `u'nimpeded discharge ofthe liquid outwardly is ensured in every zone of the materialcentrifuged.V The eect is as if a sponge filled with liquid is compressed. I

The bores Vor recesses c may be of `various dimensions and Vmay be arranged relatively to one another in any desired manner depend-4`v ing upon the particular end in view.

In order to make it impossible for ,lighter constituents in the material centrifuged to emerge through the water withdrawal tubes c, a fine mesh wire, gauze or filterclothd may be inserted in the interior of said tubes, said vinsertion may lbe held in position by a perforated tube e. y i

The liquid emerging from the water withdrawal tubes a is caught in any appropriate manner, for example by a trough 7 at the periphery of the centrifuge and is led away therefrom.

Cleaning of the tubes a .may be performed by washing them out with water forced in under pressure from outside, the centrifuge being stationary and the tubes a may be provided with suitable connections for this purpose.

Any number of such water withdrawal tubes may be provided as required and they may be arranged, with material from4 which it is diliicult to remove the water, in both the upper and lower cups or cones of the centrifuge or also at the cylindrical peripheral surface of a drumcentrifuge.

To enable bores or orifices c flaring conically inwardly to be produced easily from the inside of a water withdrawal tube said tube a may be made in a plurality of longitudinal sections.

That I claim is 1. The combination with a centrifugal machine, comprising a rotatable drum, of means for drawing off fluid from finely granular material in said drum, said means oomprising dehydration pockets the walls of which run parallel to each other and extend into the zone of solid material, said dehydration pockets being provided with perforations in their walls, said perforations extending obliquely from the inside of the dehydration pockets toward the wallof the drum and forming an acute angle with the inner surface of the dehydration pockets.

2. The combination with a centrifugal machine, comprising a rotatable drum, of means for drawing off uid from finely granular materialin said drum, said means comprising pipes passingthrough the Wall of said drum and extending into the Zone of solid material therein, the walls-of said pipes being' perforated to permit the passage of liuid therethrough, said pipes being provided in their outer surface with spiral recesses in communication with the perfor-ations.

3. The combination with a Vcentrifugal machinecomprising a rotatable drum, of

. means for drawing ofl' fluid from finely granular material in said drum, said means oomprising pipes passing through the wall of the drum and extending into the Zone of solid material therein, said pipes havingperforw tions in the walls thereof directed at an oblique angle to the axis of the driunand in overlapping relation to each other.

4. The combination With a centrifugal machine, comprising a rotatable drum, of means for drawing off fluid from finely grani ular material in saiddrum, saidmeans comprising perforatedv pipes passing through the wall of the drum and extending intoA the zone of solid material therein, the perforations of said plpes being taperedin diameter from end to end.

LUDWIG ALTPETER. 

